This invention relates to material handling and more particularly, to a multilevel conveyor section for moving material in different directions.
Ongoing efforts to increase the efficiency and output of production operations have resulted in a continuing focus on how materials are moved in a manufacturing environment. In many environments, it is desirable to automatically move materials without human intervention. For example, parts are often buffered or temporarily stored in an interface conveyor. The interface conveyor supplies parts to and receives parts from one or more processing stations. Therefore, the interface conveyor is buffering or storing both preprocessed and postprocessed parts. Further, the preprocessed and postprocessed parts are transferred between the interface conveyor and a material handler, for example, an automated guided vehicle (xe2x80x9cAGVxe2x80x9d). In many applications, the AGV carries parts at two elevations, that is, at two different vertical levels or heights, thereby increasing the capability and flexibility of the AGV. For example, being able to buffer or carry parts on the AGV at two different heights, doubles the load carrying capacity of the AGV and permits an AGV to simultaneously transfer multiple parts with other part handling equipment, for example, the interface conveyor.
The interface conveyor loads and unloads parts respectively, to and from, the AGV at its end, whereas parts are passed to and from the processing station along the side of the interface conveyor. Hence, the interface conveyor must be capable of moving parts in two different, and normally, mutually perpendicular directions.
Known roller conveyors have crossfeed conveyors that accept parts at right angles to the direction of motion of the roller conveyor by using a plurality of powered O-ring transfers that are elevatable between certain rollers. When it is desirable to accept a part from another conveyor perpendicular to the roller conveyor, the O-ring transfers are lifted above the roller conveyor and provide a conveying motion perpendicular to the direction of motion of the roller conveyor. When the part is conveyed onto the O-ring transfers, the O-ring transfers are lowered, thereby lowering the part onto the roller conveyor for subsequent transfer by the roller conveyor. The mechanical components used by the O-ring transfers of the crossfeed conveyor require a substantial space below the top of the roller conveyor, for example, about 11 inches. Further, the space required for a motor for the O-ring transfers is about an additional 8 inches of space below the roller conveyor.
The AGV used in the application of interest carries parts on conveyors that are at two levels. A lower conveyor is about 10 inches above a floor level, and an upper conveyor is about 27 inches above the floor level. The vertical spacing between the upper and lower conveyors is about 17 inches. The parts being carried by the AGV are about 12 inches high, thus leaving about 5 inches between the tops of the parts and the top of the roller conveyor. Given the space requirements of known crossfeed conveyors associated with a roller conveyor, such known crossfeed conveyors cannot directly exchange parts with the AGV described above. Instead, an intervening material handling device has to receive the parts from the AGV and elevate the parts to the elevation of the crossfeed conveyor. Any such intervening material handling device substantially increases the cost and decreases the efficiency of the part handling process.
The most efficient transfer of parts between the AGV and the interface conveyor requires that the parts be transferred directly between the AGV and the interface conveyor without any intervening part handling. Therefore, the interface conveyor must have upper and lower crossfeed conveyors at the same height as the upper and lower conveyors on the AGV. Further, given the above dimensional parameters, the upper crossfeed conveyor on the interface conveyor must confine all of its mechanical and drive components within a space of about 5 inches. Applicant is not aware of any commercially available crossfeed conveyor that can be used with only about 5 inches of available space.
Consequently, there is a need for a conveyor system that permits a transfer of parts directly between multiple conveyors on the AGV described above and multiple crossfeed conveyors on another conveyor system without using an intervening material handling device.
The present invention provides a simple, compact, inexpensive and reliable multidirectional conveyor that can exchange parts between a roller conveyor and another conveyor perpendicular to the direction of travel of the roller conveyor. The multidirectional conveyor is especially useful for those applications in which floor space is at a premium, and it is desired to minimize the area consumed by the conveying elements.
According to the principles of the present invention and in accordance with the preferred embodiments, the invention provides a multidirectional conveyor section for moving an article in two different directions. The conveyor has a first roller conveyor mounted on a frame with at least two rollers adapted to move the article in a first direction. A first belt conveyor is mounted between the two rollers of the first roller conveyor and is operable to move the article in a second direction different from the first direction. A first cylinder is connected to the frame and has a first cylinder rod connected to the first belt conveyor. The first cylinder moves the first belt conveyor vertically between a first position above the first roller conveyor and a second position below the first roller conveyor to facilitate an exchange of the article between the first roller conveyor and the first belt conveyor.
In one aspect of the invention, the multidirectional conveyor section has a second roller conveyor mounted on the frame below the support with at least two rollers adapted to move the article in the first direction. A second belt conveyor is mounted between the two rollers of the second roller conveyor and moves the article in a second direction different from the first direction. A second cylinder is connected to the frame and has a cylinder rod connected to the second belt conveyor, the second cylinder is capable of moving the second belt conveyor between a first position above the second roller conveyor and a second position below the second roller conveyor to facilitate an exchange of the article between the second roller conveyor and the second belt conveyor.
In another embodiment of the invention, a method is provided for transferring an article between an interface conveyor and an article transporter. First, the article transporter is located adjacent one side of the interface conveyor. The interface conveyor has a first belt conveyor disposed between adjacent rollers of a first roller conveyor. The first belt conveyor is lifted to a first vertical position above the first roller conveyor and aligned with the first article conveyor on the article transporter. The article is transferred between a first article conveyor on the article transporter and the first belt conveyor on the interface conveyor. Thereafter, the first belt conveyor is lowered to a second vertical position below the first roller conveyor.
These and other objects and advantages of the present invention will become more readily apparent during the following detailed description taken in conjunction with the drawings herein.